The following relates generally to self-selecting memory cells and more specifically to memory cells with asymmetrical electrode interfaces.
Memory devices are widely used to store information in various electronic devices such as computers, wireless communication devices, cameras, digital displays, and the like. Information is stored by programming different states of a memory device. For example, binary devices have two states, often denoted by a logic “1” or a logic “0.” In other systems, more than two states may be stored. To access the stored information, a component of the electronic device may read, or sense, the stored state in the memory device. To store information, a component of the electronic device may write, or program, the state in the memory device.
Multiple types of memory devices exist, including magnetic hard disks, random access memory (RAM), dynamic RAM (DRAM), synchronous dynamic RAM (SDRAM), ferroelectric RAM (FeRAM), magnetic RAM (MRAM), resistive RAM (RRAM), read only memory (ROM), flash memory, phase change memory (PCM), and others. Memory devices may be volatile or non-volatile. Non-volatile memory, e.g., FeRAM, may maintain their stored logic state for extended periods of time even in the absence of an external power source. Volatile memory devices, e.g., DRAM, may lose their stored state over time unless they are periodically refreshed by an external power source. Improving memory devices may include increasing memory cell density, increasing read/write speeds, increasing reliability, increasing data retention, reducing power consumption, or reducing manufacturing costs, among other metrics.
Some types of memory devices may use variations in resistance across a cell to program and sense different logic states. For example, in a self-selecting memory (SSM) cell a logic state may be stored based on a distribution of charges and/or ions and/or elements within the memory cell. The manner in which a cell is programmed may affect the distribution of various materials that compose the cell, which may affect the ion migration of the cell, which, in turn, may affect a threshold voltage of the cell. The threshold voltage may be related to or indicative of the logic state of the cell. Small variations in threshold voltages between different logic states may therefore affect the accuracy with which cells may be read.